Jokingly describing some one with narrow mind of the world, or have low understanding on everything, or some one with idiotic behaviors or mind. Single-digit refers to a number from 0 to 9.

A person with the IQ level between 0 to 1. Used jokingly or with a despiteful overtone to describe some one with absolutely stupid or silly behavior or extremely low intellectual level. Some one who is idiotic. Could also be used to describe a narrow minded person whose view of the world is only black and white, and nothing in between.

a person with a single digit IQ

Someone who imagines himself as a daredevil and quite witty...but in actuality he is a snot nosed, sniveling coward and a mamma's Boy, who still shits & pisses his diaper. He also has a single digit IQ and smells like an open sewer!

A person may be considered a Carthew if they bear the following characteristics:

1) In an argument, must have a droopy face, and in all circumstances, must insist that they are correct,
2) Insert their digits into the crevices of morbidly obese transgender individuals,
3) Must violate underage females as they lay unconscious from over consumption of alcoholic beverages,
4) Must have an IQ of no more than a single digit,
5) Must have fondled oneself over ones sisters profile picture,
6) Must lose consciousness after one alcoholic concoction or less,
7) Must ride a naked pony,
8) In all circumstances must appear to act as gormless as physically (and mentally) possible!